Preheat oven to 350 degrees and line two large baking sheets with parchment paper.
In a large mixing bowl, whisk together flour, oats, baking powder, cinnamon and sea salt.
In a standing mixer, or in a bowl with a hand mixer, combine butter, goat cheese and coconut sugar. Cream ingredients together on medium-high speed until mixture lightens in color and has a fluffy texture, approximately 1 minute.
Turn mixer to medium-low speed and add extract and egg yolk. Mix just until batter regains its fluffy consistency, 15-20 seconds.
Fold wet batter into dry ingredients. This is a dry batter, so be patient--it will all come together!
Fold in blueberries and coconut flakes, if using. Grab a small bowl of water and place it next to your lined baking sheets.
Scoop one tightly packed tablespoon of dough per cookie onto baking sheet, leaving at least 1 inch between each. Dip tablespoon in water periodically to help prevent sticking.
Dampen fingers and smooth out edges of the cookies as well as flatten the tops. You should have 1 1/2 inch wide cookie "discs".
Bake cookies for 7-9 minutes, 7 if you like a softer cookie (my preference) and 9 if you like a chewier, crispier cookie.
Allow to cool on slotted trays (ideally, but not crucial, can just cool on baking sheets) 10 minutes before enjoying.